Welding mechanism



Sept. 13, 1949. F. H. .JOHNSONl WELDING MECHANISM 2 Sheets-Sheet 1 FiledNov. 18, 1946 INVENTOR. Haie/*26,2 /ZJ/rfa/z F. H. JOHNSON WELDINGMECHANISM Sqn. 13, 1949,

2 Sheets-Sheet 2 Filed Nov. 18, 1946 I N VEN TOR.

patented Snept. 1K3, 1949 UNITED STATES PATENT OFFICE WELDING MECHANISMFrederick H. Johnson, PleasantRidge, Mich.

Application November 18, 1946, Serial No. 710,437

(Cl. 21B-4) 15 Claims.

The present invention relates generally to electric welding mechanismsand is particularly directed to the provision of a machine and apparatustherefor embodying improvements over the structure disclosed and claimedin Purat Patent No. 2,372,117 granted March 20, 1945.

The principal objects of the present invention are: to provide a weldingmachine having a plurality of unitary independent welding heads whichmay be removed and replaced with a minimum ofeffort; to provide such amachine in which the unitary welding heads may be individually adjusted;to provide such a multiple-head welding machine in which the number ofheavy welding current conducting leads are reduced to a minimum; toprovide such a multi-element welding machine in which the individualwelding heads are each carried by a common current conducting bus; toprovide such a multiple welding machine in which each of the individualunitary welding heads contains its own welding current control switchwhereby relatively small fluid conveying conduits or electrical controlcircuits may be led to individual welding heads to control the action ofthe same rather than the more cumbersome and expensive large weldingcurrent -conducting busses; to provide a composite welding head which iseasily and economically fabricated and installed; to provide such acomposite welding head having a current conducting base supporting anelectrode positioning member and also supporting a current controllingmember having an element engageable with the base whereby the electrodesmay be selectively energized by control circuits; to provide a generallyimproved welding mechanism of the class described. Further objects willbe apparent from the specication and appended claims.

A preferred but illustrative embodiment of the invention is shown in theaccompanying drawings throughout the several views of whichcorresponding reference characters are used to designate correspondingparts and in which:

Fig. 1 is a partial diagrammatic view of a welding machine embodying theinvention,

Fig. 2 is a View in partial central vertical section of a welding headembodying the invention,

Fig. 3 is a plan View of the welding head of Fig. 2,

Fig. 4 is a diagrammatic View of a plurality of welding heads assembledto a common bus, and

Fig. 5 is a diagrammatic View showing a modied form of control for thewelding head.

It will be appreciated from a complete understanding of the presentinvention that the im-` provements thereof may be embodied in variousforms and may be utilized for various speciiic purposes. By way ofillustration but not of limitation, the invention is herein disclosed inconnection with a machine of the same general type as is disclosed insaid Purat patent.

Referring to the drawings, the present machine comprises generally asupporting frame structure 2 upon which is located in a xed manner, butelectrically insulated therefrom, a, rst current conducting bus 4 whichis located above and in spaced relation to a table portion or worksurface 6 on which is carried a second current conducting bus 8, andwhich bus 8 is electrically insulated therefrom, as by insulation I0.Preferably the busses 4 and 6 extend in spaced parallel relation andhave current conducting lead portions I2 and i4, respectively, which maybe connected to a sultable source oi welding energy, such as a weldingtransformer or welding battery. A plurality of unitary welding heads,generally designated 2li, are each suitably secured to the lower surfaceportion of the bus 4, as by a bolt 22, whereby a welding electrode 24carried by each of the heads 2|! is operable to engage a, workpiece, notshown, which is in electrical contact making engagement with the lowerbus 8. As shown, the bus 8 has a plurality of upstanding fixed weldingelectrodes 26v which are in vertical alignment with the movableelectrodes 24 and upon which the workpiece to be welded is placed. It isto be distinctly understood, however, that in many instances it may bedesirable to omit the electrodes 26 for the particular type of weldingto be desired, and in other instances it may be desirable to place theelectrodes 2s out oi vertical alignment with the movable electrodes 24.It will be appreciated while the electrodes 24-26 are illustrated asbeing in a straight row, other relative positionings may be reverted to,depending upon the shape of the work.

means 3B is carried by the stationary portion 38 of the electrodepositioning member 30 whereby a contact member carried by the means 36may be selectively brought into engagement with a plate-like base member42 of the welding head 20 which plate-like base member 42 is preferablymade of good electrical conducting material and,

3 is held in face-to-face engagement with the bus 4 by means of thepreviously mentioned bolt 22. The contact member positioning means 36 isactuated by means of uid supplied from a uid conveying conduit 44.

Fluid from a suitable source of pressure is admitted to a commonmanifold 50, which is in open communication with all of the conduits 32,so that when fluid pressure is admitted thereto, as by the controllingvalve 52, all of the electrode positioning members are actuated wherebyall of the electrodes 24 are moved into engagement with the workpiece tobe welded. Each of the fluid conveying conduits 44 are individuallyconnected to a distributor 64 which distributes fluid pressure from acommon source to one or more of thecontact member positioning means 36whereby one or more oi the contact members 40 are moved into engagementwith their respective base members 42 for connecting their respectiveelectrodes 24 to the common bus 4 whereby current nows from the bus 4 tothe bus 8 through the workpiece between the respective electrodes 24 and26 to accomplish the weld.

Referring more specifically to the unitary welding heads 26 and stillmore specifically to the electrode positioning members 30 thereof (whichmembers 3E are disclosed and claimed in cepending application, SerialNo. 650,632, iiled February 2'1, 1946, now Patent No. 2,465,456, datedMarch 29, 1949), the member 30 comprises a stationary member 38 which isin the form of an open-ended cylindrical member the upper end of whichis re- CTI ceived within a recess v60 opening outwardly through thelower surface 6l of the member 42. The member 38 extends substantiallyperpendicularly to the surface 6l and positioned therein is a pistonmember 62 which has a piston rod E4 extending outwardly from the loweropen end of the member 38. The outwardly vextending portion of thepiston rod 64 carries the previously mentioned electrode carrying member34. An insulator 61, which may be in the form of a washer through whichthe piston rod '64 is slidable, is preferably interposed between members34 and 38.

The upper end Vof the piston rod 64 is guided for reciprocal movementwithin the member 38 by the piston member 62, which is fabricated ofelectrical insulating material;V and, the lower end of the pi'ston rod64 adjacent the 'lower open end of the member 38 is supported 'forreciprocal movement by an annular vguide or bearing member 466,'which isalso fabricated from electrical insulating material, whereby the pistonrod 64 and the electrode carrying member 34 connected thereto areinisulated from the member 38 and the base mem- -ber 42. A retractingspring 6`8is positioned under tension between the piston, member v62'and the lguide member 66 whereby the piston member 62 and itsassociated rod 64 is continually urged in one direction which, as shown,is in the electrode retracted direction. The diameter of ithe spring 68is such that when it is engaging the rod 64 it will not engage the innerwall of the member 38 or conversely the diameter of the spring 68 maykbe sufficiently great so that when it is in engagement with the innerwall of the member 38 it will not engage the rod 64. p

Fluid is admitted to 'the chamber 69 Within the member 3B above thepiston member 62 through an aperture 18 opening through the upper faceof the base member 42. This aperture 10 is suitably internally threadedfor receiving the externally threaded end'of the 'conduit 32.

L. insulated from the bracket 14.

A suitable bracket I4 is rigidly secured to the lower end of the member38, as by welding, and underlies an extending portion of the base memberi2 and carries the contact member positioning means 3S. The means 36comprises an openended cylindrical member in which is positioned apiston member 82 also fabricated of an electrical insulating material. Apiston rod 84 is suitably carried by the piston member 82 and extendsdownward therefrom and outward through the lower open end of thecylindrical member 86. A reduced diameter portion of the rod 84 extendsthrough an aperture 81 in the bracket 14. The shoulder 88 formed at theintersection of the normal and reduced diameter portions of the rod 84seats against an annular insulating member 89 which abuts the upper faceoi the bracket 14. The rod 84 is clamped to the bracket 14 by a nut 90which seats against a secondannular insulating member or washer 9|abutting the lower face of the bracket 14. The bracket member aperture81 is of greater diameter than Vthe reduced diameter portion of thepiston rod e4 so that the piston rod 84 is secured to but The member 89is of suiiicientdiameter so that, when the cylindrical member 80 is atits lowermost position, it seats against the member '89 and ismaintained electrically insulated from the bracket 14. An adapter SE forholding the contact member 40 is suitably secured to the upper end ofthe cylindrical member 80 and has a reduced diameter portion e8whichvt'elescopes within the upper end of the member 8U. The telescopingportions are suitably welded together to provide a closed upper end forthe member 80. A chamber 99 is provided within the member 80intermediate the piston member 82 and adapter 96 which is in opencommunication with the conduit 44 through a passageway IUD.

fIfhe contact member 40 is carried within a recess. in the upper end ofthe adapter 96 and isvengageable, upon upward movement of thecylindrical member 80 and adapter 96, with the vlower tsurface El of thebase member 42 for establishing an electrical circuit between the member442ar1d theadapter 96. The adapter S6 and velectrode carrying member '34each have project- 'ing contact lugs 106 and |08 respectively, which'are interconnected by means of a laminated, flexible current-conductingcable I l 0.

It is believed that Ythe remainder of construetional ,details may bestbe understood by adescription of the operation .of lthe welding machine.A workpiece is rst placed upon the electrodes@ "and positioned in thedesired manner with respect thereto; and then the controlling valve 52is energized to supply fluid pressure to the manifold 5), at which timefluid under pressurezpasses into vthe chambers 6e, forcing the members52 downwardly and the welding electrodes 24 associated therewith intoengagement with the upper lsurface ofA the workpiece. Next the4distributor 54 lis controlled so that fluid pressure is supplied to theone (or more) of vthe vmeans 3S associated with the electrode l24 whichis to be energiaed, whereby the contact member 4G associated therewithis moved upward into engagement with the associated base member 42establishing an electrical Icircuit from the bus 4 through thebasemember42,'the contact member 4Q, the adapter iSlt'he cable 'HB vto theelectrode carrying Imember 34. Next the main welding current 'controllswitch SWI is closed thereby inititng'a flow'f Welding urent throughthe `cation with the manifold electrodes 24 and 26 associated with oneor more of the welding heads 20 in which the contact member positioningmeans 38 has been energized. After the completion of this weld, the mainwelding current control switch -SWI is opened and then the one (or more)of the control means 36 which was just energized is de-energizedallowing a spring H2 therein to move the associated adapter 96 andcontact member e!! downwardly so that the electrical circuit between theadapter 96 and the base member 42 is open. At the same or subsequenttime, another (or others) of the control contact member positioningmeans 36 is energized in a manner similar to that just describedbringing another one (or more) of the contact members lll intoengagement with the respective base member 52 to energize another one ormore of the electrodes g4, after which the mainy current controllingswitch SWl is again energized to initiate another weld.

It will be neces that in the Structure just ce- `scribed and where airor a gaseous fluid is used -as the actuating medium for the controlmeans 3G, it may take'an appreciable length of time to fill the entirelength of conduit 44, from the head 2id to the distributor 54, withfluid to move the associated contact member ii into engagement with itsassociated base member t2. It may be desired in some instances to speedup this operation and in such event the fluid distributor, as shown, maybe replaced by an electrical distributor and an individual solenoidvalve may be inserted in the conduit 44 immediately adjacent eachadapter e6. In this construction each of the solenoid'valves H4 issupplied with fluid pressure from a common manifold I I6. The solenoidvalve H4 is a three-way type which when energized, opens the manifold H6to the passageway it and, when cle-energized, closes its communil IS andopens the passageway It@ to atmosphere whereby the nuid pressure withinchamber Sii may be relieved. With this modified construction, it will benoted that a much shorter length of fluid conducting passageway 44 needsto be exhausted and to be filled each time the control means 36associated therewith is actuated.

As most clearly appears in Figure 3, the previously mentioned mountingstuds 22 are received in corresponding slots 23 provided therefor in thei -supporting member 42. With this arrangement,

sition an electrode in a work engaging and a if retracted position, saidpositioning means being adapted to be supported upon the framework of awelder, an electrical conducting member positioned adjacent saidpositioning means, an

electrical circuit controlling means carried by i said positioning meansas an integral part thereof, said controlling means being engageabiewith said conducting member to complete an electrical circuit, and acurrent conducting path for con-- ducting current to the electrode fromsaid circuit controlling means.

2. In a welding mechanism, the combination of an electrode positioningmeans operable to position an electrode in a work engaging position andin a retracted position, comprising a movable electrode carrying memberand a inember adapted to be supported on the framework of a welder, anenergizable electrical circuit controlling means carried by saidframework supported member, and means providing a current conductingpath from said circuit controlling means to said movable member.

3. In a welding mechanism, the combination of a supporting structure, acurrent conducting bus carried by said structure, an electrodepositioning means having relatively movable members, one ol said membersbeing adapted to carry a welding elect-rode and operable to be movedinto a retracted and an operative position, means securing the .other ofsaid members to said structure adjacent said bus, a contact member,means carried by said other member and operable to move said contactmember into electricalconducting engagement with said bus, and meansproviding a current conducting path including said contact memberwhereby the llow of welding current is controlled by the position .ofsaid contact member relative to said bus.

4. In a welding mechanism, the combination of a supporting structure, acurrent conducting bus carried by said structure, an electrodepositioning means having relatively movable members, one of said membersbeing adapted to carry a welding electrode and operable to be moved intoa retracted and an operative position, adjustable means securing theother of said members to said bus, a Contact member, luid actuated meanshaving a pair of relatively movable members, one of said pair of membersbeing carried by said other -f member, the other of said pair of membersbeing operable to move said contact member into electrical conductingengagement With said bus, and means providing a current conducting pathincluding said contact member whereby the flow of welding current iscontrolled by the position of said contact member relative to said bus.

5. A unitary welding head comprising a pair of relatively movablecio-operating members, one of said members being adapted to carry awelding l electrode, the other of said members being of electricalconducting material and forming one electrode of a switch means, meanson said other member whereby the head may be adjustably positioned on acurrent conducting supporting member forming part of a welding circuitand a second electrode of said switch means carried by said other memberand movable into engagement with said one electrode for controlling nowof welding current through the head.

6. A unitary welding head adapted to be secured as a unit to asupporting structure adjacent a current conducting bus, comprising acurrent conducting member adapted to be secured in electrical conductingrelation to said bus whereby the head is flxedly supported by and saidconducting member is electrically connected to the bus, means rigid withsaid conducting member and having a relatively movable element adaptedto carry a welding electrode and movable between a working position anda retracted position, a contact member, means carried by said rigidmeans for selectively positioning said contact member in an electricalcircuit making position with said conducting member and in a noncircuitmaking position, and means providing an electrical conducting path fromsaid contactl member and in a noncircuit making position, and meansproviding an electrical conducting path from said contact member to saidmovable element.

anni

7. A unitary wel ding head adapted to be secured es a unit to asupporting structure adjacent a current conducting bus, comprising acurrent conducting member adapted to be secured in electrical conductingrelation to said bus whereby the head is xedly supported by and saidconducting member is electrically connected to the bus, means rigid withsaid conducting member and having a relatively movable element adaptedto carry a welding electrode and movable between a. Working position anda retracted position, a contact member, fluid actuated means comprisinga piston structure and a cylinder structure, one of said structuresbeing carried by said rigid means, the other end of said structuresbeing movable relative to said one structure for selectively positioningsaid contact member in an electrical circuit making position with saidconducting mem ber and in a noncircuit making position, means providingan electrical conducting path from said actuated means carried by saidmember and .hav-

.ing a movable element adapted to position `an electrode in awork-engaging 'and a retracted posi tion, means 'providing a currentconducting path to the electrode, a contact member controlling currentflow through said path, and actuating r:

means carried by said vfluid actuated means for moving said contactmember into circuit making and circuit breaking positions.

9. .A unitary fluid actuated welding .head comprising a current'conducting plate-like member provided with means for adjustablysecuring one surface ofthe same 'to a current conducting bus, a liirst'piston cylinder secured to said member and extending outwardly of thesurface 'of said member opposite said one surface, .n first piston insaid cylinder fand .having fa piston rod, a portion of said rodextending outwardly of ysaid cylinder, means on said rod extendingportion adapted to support :a welding electrode, 'a second 'pistoncylinder, a second -piston .in said second cylinder and :e

lhaving a 'piston rod, means holding the rodof said second 'piston .inxe'd position relative to said first cylinder, contact means carried by'said second cylinder and engageab'le withsaid conducting member toclose an "electrical circuit therebetween, and Acurrent; conductingmeans electrically connecting said contact means to l'said electrodesupporting means.

10. A unitary iiu'id actuated welding coinprising a 'current 1conductingbase member :havin-'g means 'whereby it may be secured to :a ouvrentconducting bus, ain electrode supporting means carried by said basemember and operable to position an electrode in -a work-engagingposition and in 'a work-retracted position, and a contact membersupporti-ng means carried :in fixed position 'relative to :said Abasemember and Koperable `imsiticn said ycontact member in circuit closedand :circuit open position with respect to 4said base linember.

il. A unitary ii-uid actuated 'welding head 'comprising fa "currentconducting base member llavin'g means whereby it may be secured to =acurrent conducting bus, an electrode supporting means comprising acylinder carried by said base member and having a movable piston element0perable to position an electrode in a work-engaging position and in awork-retracted position, a contact member supporting means carried infixed position relative to said base member and operable to positionsaid Contact member in crcuit closed and circuit open position withrespect to said base member, means electrically insulating said elementfrom said base member, and means electrically connecting said contactmember with said element.

12. .In a welding mechanism, a supporting structure, a plurality ofcurrent conducting busses, at least one of said busses beingelectrically insulated from said structure, a plurality of unitarywelding heads, each of said heads comprising a current conducting basemember carried by a first of said busses, each of said heads comprisingan electrode operable to engage a workpiece in electrical contact with asecond of said busses and comprising an electrode position- Sing meanscarried by said base member and operable to move the electrodeassociated therewith into work-engaged and work-retracted positions,

a common source of energy for actuating said positioning means wherebysaid electrodes are concurrently in said \vorkengaged and saidworkretracted position, a contact member carried by a contact memberpositioning means, said Contact member positioning means being carriedby said base member but electrically insulated thereirom and operable tomove said contact member into engagement with said base member wherebyan electrical circuit to the associated one of said electrodes iscontrolled, and means for selectively actuating said Contact memberpositioning means.

13. A unitary fluid-actuated welding head comprising acurrent-conducting base member having means whereby it may be secured'to a 4current-conducting bus, a rst member having an elongateddownwardly-opening chamber carried by said base member, a piston in saidchamber of electrically-insulating material and cooperable with theportion of said chamber intermediate saiol piston and said base memberto form a pressure-chamber portion, a piston rod carried by said Vpistonand extending outwardly of the open end of said chamber, an annularmember of velectrcally-insulating material cartried within said 'chamberintermediate said open end and said piston, said rod extending throughthe central opening of said annular member, re-

.aillent .means interposed between said annular member and said pistonfor 'urging said piston in ione direction, electrode-holding meanscarried by the portion -of said rod extending outwardly of 'saidchamber, Ia second member .supported by said iirst member for reciprocalmovement toward and away from said base member, a contact carried by.said second .member and engageable with said 'base member to completean electrical circuit therebetween, and current-conducting meanselectrically connecting said Contact with said electrode-holding means.

14. A unitary fluid-actuated `welding head comprising acurrent-conducting base member having means whereby it may vbe securedto a current-conducting bus, a rst member having an elongateddownwardly-opening chamber carried by said base member, a piston in saidcham- :ber fof eiectrically-nsulating material and coopera'ble withtheportion of said chamber inter- `mediate `-said piston andisaid basemember Vto Aform a pressure-chamber portion, a piston rod fcsrried bysaid piston and extending outwardly of the open end of said chamber, aguide member of electrically-insulating material carried by said rstmember and adapted to guide said rod electrode-holding means carried bythe portion of said rod extending outwardly of said chamber, a secondmember supported for reciprocal movement toward and away from said basemember by said first member, a contact carried by said second member andengageable with said base member to complete an electrical circuittherebetween, and current-conducting means electrically connecting saidcontact with said electrode holding means.

15. A unitary fluid-actuated Welding head comprising acurrent-conducting base member having means whereby it may be secured toa current-conducting bus, a first member having an elongated downwardlyopening chamber carried by said base member, a piston in said chamber ofelectrically-insulating material and cooperable with the portion of saidchamber intermediate said piston and said base member to form a pressurechamber portion, a piston rod carried by said piston and extendingoutwardly of the open end of said chamber, a guide member ofelectrically-insulating material carried by said first member andadapted to guide said rod electrode-holding means carried by the portionof said rod extending outwardly of said chamber, a supporting membercarried by and extending laterally of said first member, a, secondmember located intermediate said supporting member and said base memberhaving an elongated downwardly opening chamber, a piston in saidsecondmember chamber, a piston rod carrying said second-named piston andhaving a portion extending outwardly of said second-member chamber, saidsecond-named rod extending portion being secured to said supportingmember whereby when fluid under pressure is admitted to saidsecond-member chamber above said secondnamed piston said second memberwill be moved toward said base member, a contact carried by said secondmember and engageable with said base member to complete an electricalcircuit therebetween upon movement of said second member toward saidbase member, and currentconducting means electrically connecting saidcontact with said electrode-holding means.

FREDERICK H. JOHNSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,244,508 Von Henke et al June 3,1941 2,287,945 Purat June 30, 1942 2,372,117 Purat Mar. 20, 1945Certcate of Correction Patent No. 2,481,844 September 13, 1949 FREDERICKH. JOHNSON It is hereby certified that error appears in the printedspecification of the above numbered patent requiring correction asfollows:

Column 6, line 72, beginning with the words and in strike out all to andincluding member in line 74;

and that the said Letters Patent should be read with this correctiontherein that the same may conform to the record of the case in thePatent Ofce.

Signed and sealed this 10th day of January, A. D. 1950.

[SEAL] THOMAS F. MURPHY,

Assistant Uommz'ssz'oner of Patents.

Certificate of Correction Patent No. 2,481,844 September 13, 1949FREDERICK H. JOHNSON It is hereby certified that error appears in theprinted specication of the above numbered patent requiring correction asfollows:

Column 6, line 72, beginning with the Words and in strike out all to andincluding member in line 74;

and that the said Letters Patent should be read with this correctiontherein that the same may conform to the record of the case in thePatent Oflice.

Signed and sealed this 10th day of January, A. D. 1950.

THOMAS F. MURPHY,

Ass'isant Uommz'ssz'oner of Patents.

